Already known from French Pat. No. 863,760, is a device of the type mentioned which is intended for fixed installation and displaying polygon or star-shaped knives supported on a shaft, with puncturing blades distributed evenly over the circumference, wherein the blade group is adjustable in height relative to the fixed slot plate by means of two vertical threaded spindles arranged at either side of the slot plate. With this, however, after each adjustment in height of the blade group, the parallelism between the blade group and slot plate must again be re-established because the settings of both threaded spindles are synchronized to each other. This represents a time consuming process such that the device, as is already apparent from its fixed construction, is more aptly suited to processing plants that process larger lots of similar type fur. Moreover, the known type device is more aptly suited for cutting up furs into parallel strips, less favorable, however, for introducing trim patterning slits because, with rotating polygon or star-shaped knife blades only puncture cuts are possible which, perforce, lead to damaging of the thick underlying wool and whereby whole tufts of hair can fall out. Nor can this be prevented by any precise determination of a desired projecting length for the knife blades above the convex side of the slot plate.
Lightweight devices, in the form of manually operated tools for cutting up a fur into parallel strips, are already known from German Pat. No. 907,211. One such kind of tool includes a group of circular knife blades whose positioning in height is adjustable relative to a front and rear holddown roller for the back side of the fur, and which are parallel to the group of knife blades. However, a tool of this type is not suitable for trim patterning, even if we were to substitute for the circular knife blades, knife blades that are polygon or star-shaped, somewhat like the kind in French Pat. No. 863,760, since, in this manner, only puncture cuts could, perforce, be generated.
Known from U.S. Pat. No. 2,464,206 is a device in the form of a manually operated tool that includes a group of draw-knife blades arranged at equal intervals next to each other and aligned parallel to each other, along with a handle, so that, when trim patterning, several series of cuts can be made simultaneously in the back side of the fur. The depth of penetration of the knife when working with the tool is, however, not established by the device and depends solely upon the handling by the operator so that guidance of the tool, similarly as in the case of the likewise known trim patterning knife with only one knife blade, requires considerable experience in order to execute trouble-free draw cuts without damaging the underlying wool of the fur.